Information

This is a summary of preliminary results from a lab-scale experiment investigating the suitability of black soldier fly frass as co-substrate in anaerobic digestion of cattle slurry. The experiment was conducted from December 2020 to February 2021 at the Department of Microbiology, University of Innsbruck. The frass was obtained from an industrial-scale rearing experiment, during which different pre-treatment options for improved larval bioconversion of agro-industrial wastes were investigated.

Abbreviations:

  • CS: Cattle slurry (control)
  • WB: Fresh wheat bran/grain product mix
  • WBF: Wheat bran/grain product mix digested by larvae (frass)
  • CHF: Wheat bran/grain product mix amended with biochar and subsequently digested by larvae (frass)
  • FEF: Wheat bran/grain product mix after lactic acid fermentation and subsequent digestion by larvae (frass)


co-substrates



Cattle slurry and co-substrate characteristics

Phyiscochemical characterization of cattle slurry and co-substrates



Biogas composition

Methane (CH4), carbon dioxide (CO2), oxygen (O2), and residual gases



Biogas volume

Amount of biogas generated in 24 hours





Physicochemical parameters

pH and electric conductivity




Water content, dry matter, inorganics, and volatile solids




Carbon and nitrogen content